Re: [APML]: Guiding

[Andy Wallace <andywallace@home.com>]

The Astro-Photography Mailing List
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To second Phillip's views on the need for a top of the line well-made
and rigid OAG-I have an 18" DOB that I collimate with a laser.  The
scope has an 80" focal length and its collimation is very sensitive to
the slightest pressure, for example, of an eyepiece locking screw--if
not balanced on both sides of the eyepiece, the collimation will be
thrown off which is very easily seen with the laser. I'll bet that with
most SCT's, perfect collimation at the eyepiece or at the film plane or
on the CCD chip is more a matter of luck than design. Andy

Philip Perkins wrote:
> 
> The Astro-Photography Mailing List
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> > Why not just tell us what the problems with the Celestron OAG are?
> 
>
> Philip Perkins  --  philip@astrocruise.com
> 51 27'N 1 36'W  --  Wiltshire, UK
> 43 54'N 5 32'E  --  Luberon, France
> Astrocruise     --  http://www.astrocruise.com